Hydraulic grinder



June 1929. J. E. GREENSMITH HYbRAULIc GRINDER Filed April 19, 2 l2Sheets-Sheet l June 1929- J. E. GREENSMITH 1,718,554

HYDRAULIC GRINDER Filed April 19, 1 2 12 Sheets-Sheet 2 mqmx b% vHHMWHMHV June 25, 1929. J. E. GREENSMITH 1,718,554

HYDRAULI C GRINDER Filed April 19, 1920 12 Sheets-Sheet 3 Y WI/67225 7uwwmii June 25, 1929. J, E. GREENSMITH 1,718.554

HYDRAULI C GRINDER Filed April 19, 1920 12 Sheets-Sheet 5 gl a ziiv J25, 1929- J. E. GREENSMITH 1.718.554

HYDRAULI C GRINDER Filed April 19, 192 12 Sheets-Sheet 6 June 1929- J.E. GREENSMITH HYDRAUL I C GRI NDER ,Wl @w June 25, 1 J. E. GREENSMITHHYDRAULIC GRINDER 12 Sheets-Sheet 8 Filed April 19, 1920 7521' a?ZZZVQMZZ Filed April 19, 1920 12 Sheets-Sheet 9 1 W f gx I 1 I l I l IJune 25, 1929.

J. E. GREEN SMITH HYDRAULI C GRINDER l2 Sheets-Sheet 10 Filed April 19,1920 aty.

June 25, 1929. .1. E. GREENSMITH HYDRAULI C GRINDER Filed April 19. 192012 Sheets-Sheet ll June 25, 1929. J, E. GREENSMITH 1,718,554

HYDRAULIC GRINDER Filed April 19, 1920 12 Sheets-Sheet l2 W42; 59%?az-z-j Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

JAMES E. GREENSMITH, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR, BY DIRECTAND MESNE ASSIGNMENTS, T0 BOSTON SCALE & MACHINE COMPANY, OF BOSTON,MAS- SACHUSETTS, A CORPORATION OF MASSACHUSETTS.

HYDRAULIC GRINDER.

Application filed April 19,

This invention relates to grinding or abrading machines, and with regardto certain more specific features thereof tofluid-pressureoperated-grinding or abrading machines.

The invention has for one of its objects the provision of a reliablyeffective fluid-pressure feed for the operating tool of a machine of thecharacter above mentioned, and more particularly the inventioncontemplates the idea of hydraulic means for steadily and continuouslyreciprocating a ram or slide which carries the active tool of themachine, without noticeable shock or vibration. Other objects of theinvention are to provide reliably operative means to easily control thespeed and range of movement of the tool-carrier, to effect automaticallya rectilinear reciprocatory movement of said tool-carrier withoutimpairing the action of the hydraulic system, and whereby the feed ofthe work table of the machine is placed under the control of the feedingmeans for the tool-carrier, so that the work table or its carrier may befed automatically at predetermined intervals and the time and extent offeed of the work table may be governed primarily by the same means asgoverns the movement of the tool-carrier.

It is another object of the invention to provide simple and reliablyoperative means for rotating the grinding tool and the work table, incombination with the means, above mentioned, whereby the reciprocatoryfeed of the tool-carrier and the feed of the work table toward the toolare effected by the fluid pres sure means.

It will be apparent, therefore, that the general objects of theinvention are to improve a grinding or abrading machine by generallysimplifying the construction thereof, by designing the parts and unitsfor quick, convenient and accurate assembly, ,by introducing a feed forthe grinding tool, which permits of a maximum range of speeds,substantially any feed desired being obtainable, and the feed being of asteady and uniform character in either direction of reciprocatorymovement, and by rendering a grinding machine automatically operative toa high degree.

Other objects will be in part obvious, and in part pointed outparticularly hereinafter.

The invention, accordingly consists in the various features ofconstruction, combination of elements and arrangements of parts, which1920. Serial No. 374,815.

of various possible embodiments of the invention:

Fig. l is a view, in front elevation, of the improved grinding machine.

Fig. 2 is a view of a portion of Fig. 1 enlarged and sectioned to showmore clearly the interior construction of the tool-carrier and itsfluid-pressure feed.

I Fig. 3 is a left-end elevational view of Fig. 4 is a sectional viewtaken on the line 4-4 of Fig. 1.

Fig. 5 is a view in section taken on the line 55 of Fig. "1, looking inthe direction of the arrows.

Fig. 6 is a sectional View of the toolcarrier slide taken on line 66 ofFig. 2.

Fig. 7 is a view in section taken on a line 77 of Fig. 4. This viewshows the universal or flexible coupling between the change speedgearing and the spindle of the work holding table.

Fig. 8 is a view in section taken on a line 8-8 of Fig. 4 showing thedevices whereby the work table may be given a slight range of pivotaladjustment.

Fig. 9 is a sectional view of the reversing valve and its operatingmechanism.

Fig. 10 is a view in front elevation of a portion of the reversing valvemechanism.

Figs. 11 and 12 are fragmentary views relating t0 the reversing valvemechanism.

Figs.- 13 and 14 are views of the change speed unit showing clearly thedifferent gear changes which may be effected, and also showing the meansby which the unit may be at tached to, or detached from, the body of themachine.

Fig. 15 is an enlargement of a portion of Fig. 1, relating to the meansfor feeding the work table against the tool. a

Fig. 16 is of the mechanism shown in Fig. 15 as viewed from theright-end of the machine.

Fig. 17 is a view in section taken on the draulic system and Fig. 19 isa diagrammatic view of the reversing valve in said system.

Referring now more particularly to the drawings wherein similarreference characters refer to similar parts throughout the severalviews, it will be noted that in the present. embodiment a base ormachine bed A has mounted thereon, at the top, a tool-carrying slide B.At the left of the base (see F 1) there is mounted a second slide orcarrier C adapted to be moved relatively to the base and in a directionsubstantially at a right angle to the movement of the toolcarrier. Themachine has a main driving shaft D journalled in bearings in the endwalls of the base, and in Fig. 1 of the drawings a clutch E isillustrated which is adapted for actuation by a foot. treadle F in orderto connect and disconnect, at the will of the operator, the main drivingpulley G with the main drive shaft. From a pulley H on the shaft D isdriven the pump which circulates the lubricating or cooling medium. Froma sprocket I, fixed to the shaft D there is driven the primary shaft Jof the change speed transmission mechanism between the main drive shaft.and the work spindle. To the right of the sprocket I, as viewed in Fig.1, there is a sprocket K from which the-pump L of the hydraulic systemis driven. To the left of sprocket I is a pulley M, fixed to the driveshaft and from which the operatingtool spindle is rotated during thereciprocation of the tool-carrying slide. Within the hollow bed or baseor frame of the machine there is located an oil-reservoir N from whichis drawn and returned the fluid which is used for reciprocating thetool-carrying slide and effecting the automatic feed of the work table.This reservoir is arranged preferably at the lower part of the machineand is connected by suitable piping to the pump L then through a valvemechanism 0 to an operatingpiston and cylinder mechanism 1. Thetoolcarrying slide B is connected to a projecting stem of the piston. Achange speed transmission unit Q, is fitted into the frame of themachine through an aperture at the front thereof and is adapted forready attachment or detachment from the machine frame and the remainderof the transmission. A work carrier R comprises the slide O and aspindle carrying rocker S, there being provision for pivotal adjustmentof the latter with respect to the slide.

'The tool actuating mechanism.

In the present embodiment of the invention the tool is adapted to rotateat a relatively high speed while simultaneously traversing the work. Tothese ends (see Figs. 1 and 2) the pulley M is connected by belt 20 toan elongated pulley 21. The latter is fixed to a spindle 22 journalledat opposite ends in trunnions or bearings 23 and 24 provided in the maintool-carrier casting B. The belt 20 is held taut and restricted againstlongitudinal movement with the tool-carrier by means figuration. Thetool is suitably housed as indicated at 27 and one bearing of the toolspindle is provided with devices for taking up any looseness in thebearings.

The top of the machine frame A is provided with a dove-tail Way 28Within which is slidably fitted thedove-tail base 30 of thetool-carrier. To this base is bolted a depending ear 31 through which isprojected an extremity 32 of the stem 33 of a piston'34, which latter isa part of the fluid pressure operated apparatus of the machine. Forgiving the tool-carrier its reciprocatory movement a cylinder 35, withinwhich the piston is fitted, is provided with ports 36 and 37respectively at either end of the cylinder. To cause movement of thetool-carrier or ram in a forward direction fluid is supplied underpressure through the port 36 and is simultaneously exhausted through theport 37 at the opposite end of the cylinder. To reverse the direction ofmovement of the carrier the direction of flow of the fluid is reversed.This reversal is accomplished automatically or may be manually ifdesired through the agency of the valve mechanism 0 and its actuatingmeans (see Figs. 1, 2, 9, 10, 11, and

12) The extremity 32 of the piston stem 33 is threaded where it projectsthrough the car 31. Nuts 38 are provided on the extremity at either sideof the ear and permit. of securing the ram or slide in differentadjusted positions with respect to the cylinder. In this way provisionis made for varying the position of the Working stroke of the tool.

. The valve mechanism 0 comprises a housing consisting of a shortcylindrical tube 40 having a flange or annular lip 41 by which it issecured in an opening provided in front of the frame A, a rear closureplate 42 and a front closure member 43. Within the body 'of the housingthere is fitted a cage 44 and tion of the valve is cleared awayintermediate.

two narrow end bands 48 and 49, as indicated in Fig. 11 at 50, exceptfor small areas bordering the ports before mentioned, an area 51 whichco-operates with a port 52 communicating with the exhaust, and an area53 substantially at the top of the valve which is left for the purposeof obtaining a high degree an exhaust pipe 60. Should the valve be I thevalve parts.

turned to cause registrationof the ports 46 and 54 the fiuid will passthrough the interior of the hollow shell of the valve then outward 1ythrough port 46 of the valve plug, port 54 of the valve cage,'forward'cyliuder supply pipe 61 to the forward end of the cylinder,whereupon the piston 34 will be urged rearwardly and the tool-carrier inthe same direction. It will be noted that when these two ports are incommunication, the port 47 of the valve is moved out of registrationwith the port 55 of the valve cage which is in communication with arearward cylinder supply pipe 62. The raised area surrounding the port47 is moved beyond the port 55 of the cage so that fluid in the cylinderto the rear of the piston is permitted to exhaust through the rearwardcylinder pipe 62 through the port 55, around the exterior of the valve,pass ing by the raised areas at the ends'thereof, and dischargingthrough the port 52 of the valve cage into the exhaust pipe 60.

The direction of flow of the liquid may be reversed by a movement of thevalve to cause 7 registration of the ports 47 and 55 which will cause'arelationship of the opposite ports 46 and 54 similar to the onepermitting the exhaust just described. This improved valve constructionprovides a nicety of balance of The fluid pressure is distributed insideand outside of the valve. The fluid used having a lubricatingcharacteristic, and flowing about between the plug and the cage, causesconstant lubrication. The

' routing of the exterior of the valve leaving only the few raised areasnecessary to close, open or partition the ports, reduces friction to aminimum and the valve is setjn its different operative positions by amovement through a very slight angular range. The balance and consequentease of operation obtained by this valve structure has an importantbearing on the adaptability of the machine for work of extremeprecision. In asmuch as the tool carrier is automatic in itsreciprocatory feeding movement, and the reversal of its movement at eachextreme is under its own control through the medium of the valve, it ishighly advantageous to reduce the burden of the valve operation to thelowest possible point. In so doing there is maintained in the hydraulicsystem a uniformity of pressure which obviates surging and unevenfeeding.

The fluid is supplied from the pump L through an inlet pipe 65 threadedinto the rear closure plate 42 of the valve. From an inspection of Fig.9 of the drawings it will be apparent that the fluid is discharged therefrom into the interior of the valve 45. Passing through the registeredports it finds its way to one end or the other of the cylinder accordingto which ports are in registration and the fluid at the opposite end ofthe cylinder respectively is exhaustedthrough another portion of thevalveand exhaust pipe 60. It is only when the valve is moved to registerone pair of ports as an inlet to one end of the cylinder that theexhaust passage through the valve is opened, therefore the liquid in theexhaust end of the cylinder is confined therein except when the fluid isbeing supplied under pressure to the other end of the cylinder. In theexhaust pipe 60 there is provided a manually operable valve forregulating the rate of fiow of the fluid through the exhaust andwhichconsequently regulates the rate of movement of the piston in thecylinder 35. The exhaust pipe 60 discharges into the container N asshown clearly in Figs. 1 and 18 of the drawings. An end thrust bearing71 is provided between the valve and the front closure member of thevalve housing,'and a conduit 72 is formed in the forward end of thevalve which permits a portion of the operating fluid to flow into achamber 78 surrounding said bearing and maintain it constantlylubricated. It will be apparent from Fig. 9 of the drawings that thereis a slight space at the rear of the valve between it and the rearclosure plate 42. There is therefore a distribution of the fluidpressure at both ends as well as within and around the valve. Thecylinder 35 is provided at either end near the top with relatively smallair vents 74 and 75 which communicate with the oil container N by meansof pipes 76 and 77, each of which is provided with a pet cock as shownat 78 in Fig. 18. The hydraulic system is also provided with a by-pass80 extending from the intake pipe to the exhaust pipe. This by-pass isnormally closed to the intake pipe by a spring pressed relief valve 81which may beregulated to permit part of the fluid to flow from theintake directly into the exhaust should the pump pressure be too highfor conditions 1n the reversing valve, cylinder or other parts of thesystem.

The reversing oaYoe operating mechanism.

The Valve 45 has a forwardly extending stem 85 which has a bearing inthe front closure plate of the valve housing. packing is provided toprevent leakage of oil and the same is heldin place by a hollow screwmember 86 tapped into the forward part of the front closure plate andbeing itself bored to serve as a part or continuation of the'bcaring forthe valve. The forward Suitable tion toward the other.

part of the front closure member 43 of th valve mechanism is formed inthe shape of a short cylindrical boss, and mounted on this boss for freerotative movement but held against longitudinal displacement is a plate87 having a central recession 88 from its upper edge, providing a yoke.The plate 87 also carries two links 90 and 91 pivotally supportedforwardly thereof as shown clearly in Fig. '10. These links have theirfree ends equipped with cam rollers 92 and 93 which are constrained tomovement toward one another by means of a spring 94 connected at eitherend to pins 95 and 96 projecting respectively from the rear wall of eachlink. An operating lever 100 is pivotally mounted on the frame of themachine,

the pivot being preferably near the top or the slide way for the toolcarriage. The lever 100 has a short upward extension beyond its pivotproviding a handle 101 by which it may be operated, and also, journalledin the rear of said upward extension is a roller 102 adapted to beabutted by actuating members or stops 103 and 104 which are adjustablyfixed on the tool carrier. The lever 100 has at its lower free extremity105 a roller 106 positioned within the recession 88 of the plate 87 andadapted to bear against one or the other of the side -vgalls of the yokeaccordingly as the lever is plvotally moving in one direction or theother. At the forward extremity of the stem of'the valve 45 there isfixed a cam member 110 having a depending arm 111. The said arm isformed with stop faces 112 and 113'adapted 'to abut adjustable stops 114and 115 provided on the front of the valve housing and consequently infixed relation with the frame of the ma-' chine. The cam member is soshaped as to urge the rollers 92 and 93 of the links of the plate 87away from each other as the operating handle is moved from one extremeposi- This movement of the links extends the spring 94 and when thehandle has reached the point predetermined as its opposite extremity ofmovement points 116 and 117 of the cam member pass by the rollers 92 and93 respectively and the spring 94 causes the rollers to become effectiveon the opposite faces of the cam to cause that member to move quickly toits opposite extremity of movement. The cam member being as beforestated fixed to the stem of the valve 45 carries the valve through arange of angular movement which breaks communication between one set ofports and effects registration of the other set of ports. The arm 111 ofthe cam member has at its lower end a spring detent 120 which during theautomatic operation of the machine is locked inoperative by the tongueand groove device indicated at 121 but which may be utilized to lock thevalve in any one of the three desired positions. The actuating blocks103 and 104, by which the handle is automatically operated, are ap pliedto the tool carrying slide by means of T-bolt locking devices, the headsof which are slidably adjustable in a T slot 122 extendinglongitudinally of the tool carrying slide. By this construction theactuating blocks may be quickly and conveniently moved to and locked inany desired position. The bodies of the actuating blocks are pivotallymounted so that if it is desired they may be swung about their pivots toa position where they will not be intercepted'by the roller 102 of theoperating lever 100 during the movement of the tool carrier. For limitmgthe extent of movement of the yoke member 87 there are provided on theflange 41 of the valve housing 40 adjustable stops and 131. Byadjustment of the set screws of these stops accurate registration of thevalve ports may be obtained.

Means are provided by which the tool-carrying slide may belongitudinally reciprocated by hand. To this end (see Fig. 6) a stubshaft 132 is projected through the frame of the machine journalled in aboss 133. This shaft carries at its outer end a hand wheel 134 and atitsinner end a pinion 135 both of which are fixed on the shaft. A rack136 is secured to the under side of the toolcarrying slide and has teethmeshing with the teeth of the pinion. If desired the shaft 132may bemade shiftable axially so that the pinion maybe withdrawn from mesh withrack 136.

The work actuating mcham'sm.

By the structure of the embodiment of the invention herein shown thework may be rotated while being acted upon by the edge of the rotarygrinding tool. There is also provision for advancing the work toward thetool at predetermined times. This advance or feed of the work may bemanually, or automatically under control of the movement of thetool-carrying slide.

As previously stated the main drive shaft is connected through chain andsprockets to a shaft J of the change speed transmission unit Q. Thisunit is shown tzlearly in Figs. 1, 13 and 14, and comprises a box orframe 140 having an arcuate front wall 141 connectible to the frame byan attaching flange 142.

In assembling the machine the transmission box is passed rearwardlythrough an aperture 143 in the front wall of the machine frame andsecured to said frame by bolts passing through the attaching flange 142into the frame. The machine frame comprises two cross struts 145 and 146and at the rear of the transmission box means are provided as indicatedat 147 and 148 for attaching same to the struts. Journalled in sidewalls 150 and 151 of the transmission box there are three shafts J, 152and 153; the

shaft J being the primary shaft which is connected to the main driveshaft. Pivotally mounted on this shaft is a rocker arm 154 whichcarries, loosely mounted thereon, a gear 155 above its pivot point and agear 156 below its pivot point. The rocker arm 151 extends forwardly inthe transmission box and has an extension in the nature of a short shaft157 which projects through a slot 158 in the arcuate front wall of thebox. Fixed to this short shaft extension outside of the transmission boxis a combined handle and detent member 160, by which the rocker arm maybe manipulated to cause engagement or dis-engagement of the gears 155and 156 with gears fixed on the intermediate shaft 152 as will moreclearly appear hereinafter. The rocker arm 15 1 may be locked in' anydesired position by a spring pressed detent pin 161 which is adapted toengage with recesses-162 properly spaced on the front wall of thetransmission box in line with the move ment of the detent pin.

A drive sprocket 170 is fixed to the primary shaft J of thetransmission. There is also fixed on this shaft two gears 171 and 172,the first adjacent the sprocket 170, and the second being of largerdiameter and adjacent the side wall 150 of the box. In permanent meshwith the small diameter gear 171 is the gear 156 which is carried by therocker arm 154 below its pivot, and in permanent mesh with the largerdiameter gear 172 is the gear 155 which is carried by the rocker armabove its pivot. On the intermediate shaft there is fixed a singlemember on which are cut two gears 180 and 181 and also fixed upon theintermediate shaft. adjacent to the side wall of the box, is a gear 182.The gear 180 is of comparatively large diameter, the gear 182 somewhatsmaller and the gear 181 comparatively small in diameter. As shown inFig. 13, when the rocker arm 15% is in its lower position with respectto the slot in the front of the transmission box the transmission iscompleted to the intermediate shaft from the large diameter gear 172 onthe primary shaft, through the gear 155 carried by the rocker arm aboveits pivot, to the gear 182 of intermediate diameter on the intermediateshaft. 1f the rocker arm is moved to its upper position thistransmission is broken and another is established from the smalldiameter gear 171 on the primary shaft through the gear 156 carried bythe rocker arm below its pivot, to the gear 180 of comparative largediameter on the intermediate shaft. By this gearing the intermediateshaft may be given either one of two speeds. I

On the shaft 153 there is splined a sleeve 190, exteriorly of whichthere is loosely pivotally mounted a second rocker arm 191. This rockerarm carries above its pivot, loosely journalled, a gear 192, and .belowits pivot, loosely journalled, it carries a gear 193 of smallerdiameter. Fixed to, or a part of the sleeve 190 there are two gears,one194, of small diameter on one side of the.r0cker arm and which is inpermanent mesh with the large gear 192 carried by the rocker arm, andthe other 195 of larger diameter which is in permanent mesh with thesmaller gear 93 carried by the rocker arm below its pivot point. Thissecond rocker arm is also provided with a shaft extensionprojectingthrough the front wall of the transmission box and the shaftextension has a combined handle and detent device attached to itcorresponding to the one attached to the'rocker arm 154. Reference toFig. 1 of the drawings will show clearly the character of the openingthrough the front wall of the transmission box. It will be noted thatthere is a main horizontal artery and four parallel slots 200, 201, 202and 203 extendin at right angles from said artery; two of these slotsextend upwardly and two downwardly. It is possible, therefore, to movethe rocker arm 191 and its sleeve 190 along the shaft 153 in order toestablish connection between the gears 192 and 193, carried by therocker arm, and either of the gears 180 or 181 of the intermediateshaft. The large gear 192 may thus be meshed with the large gear 180 ofthe intermediate shaft in which case the rocker arm shaft extension willobtain a position'at the top of slot 203. If desired the sleeve may beshifted axially to mesh the large gear 192 with the small gear 181 ofthe intermediate shaft. The shaft extension of the rocker arm will atthat time be at the top of slot 202. And so with the gear 193, carriedby the rocker arm 191 below its pivot, which may be meshed with eitherof the gears 180 or 181 of the intermediate shaft. This provides forfour different speeds of the shaft 153 from a single speed of theintermediate shaft. It

will be noted, however, that there is provision for two speeds of theintermediate shaft, and "that therefore by the gearing described eightdifferent speeds of the shaft 153 may be obtained. The latter shaft isconnected by an easily separable and flexible joint 205, a

splined sleeve and shaft 206 and a second flexible joint 207 to anoperating shaft 208 for the work table spindle (see Fig. 7). The frameof the machine and the work-carrier slide are apertured as indicated at210 permitting the transmission to extend through to the operating shaftwhich is journalled in an adjustable rocker casting 211 which latter ispivotally supported between parallel webs 212 and 213 projecting fromthe Work-carrier slide G.

. The work table spindle is indicated at 220. It has a frustro-conicalupper bearing which seats in a bearing block 221 inserted and fixed inthe top of the rocker casting 211. At its lower extremity the spindlehas a bearing in sleeve and also secure to the flange of the,

sleeve an annular member 226 having an interiorly projecting lip 227which in turn confines against vertlcal movement an interiorly threadedadjusting nut 228 while, at the same nut. The taper of the split bushing228 continues for a considerable part of the length of said bushinggandis then supplemented by a threaded portion of uniform diameter. It iswith this threaded portion that the nut 228 oooperates so that rotationof the nut, confined as it is against vertical movement, will impart avertical movement to the bushing. This will move the bushing in or outof the interiorly tapered sleeve and will accordingly constrict orenlarge the diameter of the bearing. By this construction the spindlehearing may be adjusted to the degree desired. The lower extremity ofthe spindle is threaded and equipped with suitable lock nuts and washer.About midway of the spindle a collar 230 is pinned, above which there isloosely mounted a worm wheel'23l adapted to mesh with a worm 232 of thespindle operating shaft 208. The upper surface of this worm Wheel isprovided with clutch teeth 233 adapted to cooperate with clutch teeth234 of a vertically shiftable clutch 235 splinedon the operatingspindle. This clutch is adapted for manual operation bymeans of a yoke236 pivotally mounted on an ear 237 extending inwardly from the sidewall of the rocker casting. The yoke is fixed on a short rocker shaft238 which projects outwardly through the rocker casting as shown clearlyin Fig. 1 and to which is fixed an operating lever and handle 240. Thehandle has a detent characteristic similar to others hereinbeforedescribed and the locking pin thereof co-operates with recesses in therocker casting whereby the clutch may be locked in or out of operativeposition. A work table 241 of any suitable form or' character may beattached to the upper end of the work spindle 220.

For various reasons it is desired that the work table have a capabilityof a small range of adjustment to and from a horizontal plane. In thepresent embodiment the rocker casting having a pivotal mounting at thetop of the carrier-slide has a' connection ateither side,' near thebottom of the casting, of a T-bolt and cross slot type. The slots areindicated at 242 and 243 and the T-bolt heads at 244 and 245. Atightening up on the nuts 246 will secure the .rocker in position andthe adjustment is eifected'by an adjusting bolt 247 swivelly mounted inthe rocker'casting and thread- I 250 is provided on the rocker castingwhich co-operates with an index number fixed to the slide, whereby theextent of adjustment can be determined.

As heretofore stated the work-carrier slide has a dove-tail connectionwith the frame of the machine whereby the entire work-carrier may have avertical up or down movement. At the work table end of the frame thereis a standard 251 which time permitting rotative movement of sa1dsu1tably journals a screw threaded rotatable shaft 252. At the topofthis shaft there is a beveled gear 253 which meshes with a beveledpinion 254 on the end of a shaft 255 which is horizontally disposed andjournalled in a suitable boss 256 provided on the-web 213 of thework-carrier slide. This shaft 255 has fixed on its forward end a handwheel 257 the rotation of which will cause rotation of the shaft. Thiseffects a vertical movement of the slide due to the latters connectionwith the screw threaded shaft 252 by means of an interiorly threadedboss 258 projecting from the slide and through which the .screw shaft isthreaded.

The present invention contemplates the placing of the feed of the worktable under the control of the action of the tool-carrier slide, bymeans reliably operative, simple, inexpensive, and which make for quietand nonvibratory operation of the machine. To this end a pair of cammembers 260 and 261 are adjustably fixed in spaced relation on thetool-carrier slide. Through a system of links and levers which will belater described in detail a ratchet wheel 262 loosely mounted on a stubshaft 263, carried by the slide C, is intermittently actuated. Theratchet wheel is keyed to the hub 264 of a gear 265 which is rotative onthe stub shaft 263. An arm 266 isloosely mounted on the hub 264 of thegear 265 intermediate the ratchet and the'said gear. This arm carries aspring pressed pawl 267 adapted to mesh with the teeth of the ratchetwheel 262. The free end of the arm 266 is connected by means of a link268 to one arm 269 of a bell crank lever 270. The

276. and is conne:ted to said link by a pin 277.

This link carries at its upper free end a roller 278, and intermediatethe ends of the link the same has a connection to an arm 280 pivoted tothe frame of the machine at 281. An adjustable stop 290 is provided onthe frame of the machine adapted to limit the movement of the bell-cranklever under the influence of its spring, and thereby limit theretrograde movement of the pawl. The spaced cam members 260 and 261 have0posed inclined cam faces 292 and horizontal dwells 293. As thetool-carrier slide moves under the influence of the fluid pressure andfrom right to left across and beyond the work the roller 278 will beacted upon by the 1nclined surface of the cam member 261 and urgeddownwardly in a substantially vertical direction. The arm 280 will swingon its pivot and the bell-crank lever will swing about its axis againstthe action of the spring 272. The pawl 267 being at this time inengagement with the ratchet wheel will rotate the latter a few degreesand as the tool-carrier slide continues through its active range ofmovement the roller 278 will contact with the horizontal dwell 293 ofthe cam member. This accomplishes a step of upward feed of thework-carrying slide inasmuch as the gear 265, which rotates with theratchet wheel, meshes with a gear 291 which is fixed on the shaft 255.Said shaft carries the beveled pinion which meshes with the beveled gearat the top of the elevating screw shaft 252. As

the tool-carrier slide is reversed through theaction of the automaticvalve and starts on its movement from left to right, the dwell 293 ofthe cam member 261 passes beyond the cam roller 278 and the spring 272is permitted to urge the bell-crank lever in a direction to retract thepawl for a subsequent step of feed.

This subsequent step takes place as the tool completes its grindingoperation for that direction of movement, and is effected by contact ofthe inclined surface 292 of the other cam member with the cam roller278. It will be noted that in the present embodiment a step of feed isimparted to the work table at the end of a movement of the tool-carrierslide in either direction of reci rocation. There is therefore thecondition 0 a step of feed of the work table taking place just prior tothe grinding or abrading tool beginning its action upon the work. Thetool traverses the work at any feed of speed desired, this rate of speedbeing controllable by the operator by manipulation of the valve 70. Thespeed of movement of the tool-carrier slide has a maximum range anduniformity due to the fluid pressure actuating means and the controltherefor, and it is possible to impart to and maintain a feed to thetool-carrier slide which is almost imperceptible should this be desired.The reversal of the tool carrying slide may be automatically effected bythe mechanism described and may be caused to take place at the pointdesired by adjustment of thestops 103 and 104-. The camsof thework-carrier slide feeding means are preferably adjusted in accordancewith the positions of the said stops so that the step feed of theworktable becomes effective just after the tool leaves the surfacewhichit is grinding and before the return of the tool to active grindingposition in the oppositedirection of movement. It will be noted that thetool spindle and the work spindle are rotated through mechanicalagencies while the feeding movement of both the tool carrier and thework table are effected under the control of the hydraulic system.

Should it be desired to discontinue the feed Operation and assembly.

The work table is preferably a magnetic chuck to which current may besupplied through a switch mounted on the work spindle rocker, but notshown in the drawings. The work being positioned on the table anelectric circuit is closed through the coils of the chuck by manualoperation of the switch heretofore referred to,and with a suitablegrinding or abrading tool in position on the end of the tool carryingspindle the machine 1 is started in operation by movement of the foott-readle F which causes engagement of the members of the clutch E. Fromthe main drive shaft the tool spindle is rotated at a constant speed andthe work spindle is rotated at the desired speed through havingpreviously set the transmission mechanism to engage the gears of theproper train. The automatic feed for the work table'may be in or out ofoperation as desired accordingly as the shield 300 is or is not inposition to prevent engagement of the pawl 267 with the teeth of theratchet wheel. If desired the transmission may be broken by swinging thepawl about its pivot irrespective of the position of the shield.Assuming the automatic feed of the work table to be out of operation thetool carrier slide will be reciprocated horizontally to cause the toolto traverse the rotating work piece. At the end of each movement in onedirection the work table may be given a step feed by manual operation ofthe hand wheel 257. At the point in the operation which is predeterminedas the end of the movement of the tool carrier in one direction, one ofthe operating members or stops carried by the slide picks up theoperating handle of the reversing valve and carries it beyond thecenter; the valve mechanism itself completing its throw to leg thetool-carrying slide within an exceedingly valve the back pressure of theescaping fluid of the cylinder may be increased or dimin ished to secureany desired steady speed of wide range.

Vith the awl 267 adjusted for engagement with t e teeth of the ratchetwheel, the link and lever mechanism heretofore described becomeseffective as an automatically operative feed for the work table whichfeed is underthe control of the movement of the tool carrying slide. Itis understood that fluid pressure means have been extensively employedin grinding machines but particularly for the purpose of feeding thework carrier. The present -machine employs a fluid pressure device foreffecting a reciprocatory movement of the grinding wheel carrier and bythe present arrangement the feed of the grinding wheel has a wide speedrange in both directions of movement and is particularly steady andeffective. The reversing mechanism is highly automatic and quite easy ofoperation due to the balanced charac-v ter of the reversing valve whichmakes further for a steady operation of the entire machine inasmuch as.the resistance which it offers to the tool carrying slide in itsreciprocation is reduced to a minimum. No sub-v stantial additionalburden is put upon the hydraulic system.

The change speed gears, being assembled in a unitary structure, may bequickly and conveniently removed from the machine by disconnecting thebolts which hold the transmission box to the frame; separating theuniversal joint 205 and removing the entire transmission box fromthemachine. Both spindles of the machine have one bearing which isconstructed to provide for obtaining the proper adjustment andto'compensate for wear As the means for securing the tool and work tableto their respective spindles forms no part of the present invention adescription of this means is not included herein.

As many changes might be made in the above construction and as manyapparently widely different embodiments of the invention might be madewithout departing from the scope thereof. it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What I claim is:

1. In a machine of the character described, in combination, a tool,hydraulically actuated means for reciprocating the tool across work, awork support, means for rotating said worksupport, means under controlof the eating travel, means for rotating the tool as it traverses thework, and a valve under control of the tool actuating means forautomatically effecting the reversal of movement of said tool.

2. In a machine of the character described, in combination, a tool,hydraulically actuated means for reciprocating the tool across work, awork support, means for rotating said work support, means under controlof the tool actuating means for feeding the work toward the tool at theend of the movement of the tool in either direction of its reciprocatingtravel, means for rotating the tool as it traverses the Work, ahydraulic power system, and a valve in the exhaust thereof to vary thespeed of the reciprocatory movement of saidtool.

3. In a machine of the character described,

I in combination, a tool, hydraulically actuated means for reciprocatingthe tool across work, a work support, means for rotating said worksupport, means under control of the tool actuating means for feeding theWork toward the tool at theend of the movement of the tool in eitherdirection of its reciprocating travel, a valve under control of the toolactuating means for automatically eifecting the reversal of movement ofsaid tool, a hydraulic power system, and a valve in the exhaust thereofto vary the speed of the reciprocatory movement of said tool.

4. In a machine of the character described, in combination, a toolcarriage adapted to support a rotary abrading tool, and means forcontinuously reciprocating the tool carriage and causing a cuttingaction of the tool on work in both directions of reciprocation,comprising hydraulic carriage-actuating means, devices for automaticallyeffectingv reversal of movement of said carriage at theend of its workinstroke in either direction, and mechanism for causing uniform rotationof said tool as the carriage reciprocates.

5. In a machine of the character described, in combination, a toolcarriage adapted to support a rotary abrading tool, means forcontinuously reciprocating the tool carriage and causing cutting actionof the tool on work in both directions of reciprocation, comprisinghydraulic carriage-actuating means and devices for automaticallyeflecting reversal of movement of said carriage at the end of itsworking stroke in either direction, avwork support, means for rotatingsaid work support, and means under control of the carriage actuatingmeans for feeding the work toward the tool at intervals.

6. In a machine of" the character described,

in combination, a tool carriage adapted to sup port a rotary abradingtool, means for con-

